Everyday Muscle.

Opponens Pollicis

The reason you can text, grip tools, and hold a coffee cup. Opposition is what makes human hands special.
Function
Opposes thumb — brings it across palm to touch other fingers
Origin
Flexor retinaculum and trapezium
Insertion
Lateral border of 1st metacarpal
Innervation
Recurrent branch of median nerve (C8-T1)